Laredo 315RL - air leaks around hitch

[rg2357]

I recently added an fantastic fan to my rv. I noticed when I have it in the exhaust mode and no windows open, a large amount of air flows in through screen below the refrig. I have traced this airflow to both sides of the hitch. Is that aree supposed to be sealed. I put a brite light near the hitch and can see light from inside the basement storage. Looks like a great place for insects, mice, hot or cold air to enter camper.